Re: [gentoo-user] Bluetooth speakers

[Peter Humphrey]

On Monday, 9 May 2022 15:38:30 BST Michael wrote:
> On Monday, 9 May 2022 14:56:42 BST karl@××××××××.se wrote:
> > Peter:
> > ...
> >
> > > What would help is some idea of how the whole BT system works,
> >
> > ...
> >
> > There are two incompatible types of bluetooth:
> >  Bluetooth Low Energy (BLE)
> >  Bluetooth Classic
> >
> > see:
> >  https://www.bluetooth.com/learn-about-bluetooth/tech-overview/
> >
> > You must check which generation of bluetooth your speaker uses.
> >
> > If your speaker uses the classic type, this might help you:
> >  https://wiki.debian.org/Bluetooth/Alsa
> >
> > ///
> >
> > More info about bluetooth:
> >  https://en.wikipedia.org/wiki/Bluetooth
> >  https://www.bluetooth.com/specifications/specs/
> >
> > ///
> >
> > Current linux bluetooth tools (http://www.bluez.org/) doesn't
> > handle bluetooth classic, unless you build bluez with
> > --enable-deprecated configure option.
> >
> >  Also, bluez has dropped direct /dev file access for users, you
> >
> > have to set up and go through dbus regardless wether you like it
> > or not.
> >
> > Regards,
> > /Karl Hammar
>
> I've met some success getting BT to work and I tend to follow these basic
> steps:
>
> 1. Configure the kernel according to the BT chipset available on the PC.
>
> 2. Power the BT chip by using whatever hardware button is available and
> check dmesg identified the device and loaded whatever module and firmware
> is necessary.
>
> 3. Use 'rfkill list' to check the device is not blocked and unblock it if
> necessary.
>
> 4. Run 'rc-service -v bluetooth start'.
>
> 5. Run 'bluetoothctl' to scan, list, pair and trust any peripherals  -
> exchange a PIN to facilitate pairing as necessary.
>
> These steps should be relatively easy to complete and GUI tools are also
> available to assist with the above.  Any problems thereafter are userspace
> related, i.e. whether the applications I use will be able to work with the
> BT peripherals.  Audio has been problematic on a particular use case, where
> neither alsa (bluez-alsa), nor pulseaudio allowed me to output audio via
> BT. Eventually I tried blueman which after a couple of restarts helped
> pulseaudio to recognise the device and output audio through it.

Yes, I went through all that, just as you said, but still I got no sound.

> In all cases I prefer cables to temperamental radio connectivity and where
> quality matters, like it can be in some audio applications, I would seek to
> connect with a cable.

Indeed, and I've now replaced the speakers, the 3.5mm cable and the USB 
dongle - every sound component is new. When I tested it yesterday in the 
plasma control panel, I heard one "front left", very loud, and then nothing. I 
thought some BT stuff must still be lying around somewhere, so I've installed a 
new system from scratch, using a kernel .config from before I started with BT, 
and today I still hear no sound.

This seems like witchcraft now.

-- 
Regards,
Peter.